U.S. patent number 10,107,408 [Application Number 15/444,910] was granted by the patent office on 2018-10-23 for temperature controlled purge valve with washer/o-ring seal stack.
This patent grant is currently assigned to BAKER PRODUCTS, LTD.. The grantee listed for this patent is BAKER PRODUCTS LTD.. Invention is credited to Robert Dulin.
United States Patent |
10,107,408 |
Dulin |
October 23, 2018 |
Temperature controlled purge valve with washer/O-ring seal
stack
Abstract
A temperature response valve is disclosed. The valve has a body
with an outside surface and an outlet. The valve has a sleeve that
partly engages the outside surface of the valve body to direct, via
channels on an inner surface of the sleeve, water flowing out of
the valve body outlet. The water is held into contact with part of
the outer surface and expelled at a removed end of the sleeves
where the channels open to the environment. The valve engages the
threads on a threaded male member of an outside faucet.
Inventors: |
Dulin; Robert (Kingsbury,
TX) |
Applicant: |
Name |
City |
State |
Country |
Type |
BAKER PRODUCTS LTD. |
Kingsbury |
TX |
US |
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Assignee: |
BAKER PRODUCTS, LTD.
(Kingsbury, TX)
|
Family
ID: |
59019753 |
Appl.
No.: |
15/444,910 |
Filed: |
February 28, 2017 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20170167625 A1 |
Jun 15, 2017 |
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Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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14884047 |
Oct 15, 2015 |
9822886 |
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62063985 |
Oct 15, 2014 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F16K
3/0254 (20130101); F16K 3/267 (20130101); F16K
31/002 (20130101); F16K 3/246 (20130101); Y10T
137/1189 (20150401) |
Current International
Class: |
E03B
7/10 (20060101); F16K 31/00 (20060101); F16K
3/02 (20060101); F16K 3/26 (20060101) |
Field of
Search: |
;137/301,62,216,315.28,59,79 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Venkatesan; Umashankar
Attorney, Agent or Firm: Jackson Walker, LLP
Parent Case Text
This is a continuation-in-part application, and claims priority to
and the benefit of U.S. application Ser. No. 14/884,047, filed Oct.
15, 2015; which claims the benefit of U.S. Application No.
62/063,985, filed Oct. 15, 2014, and incorporates herein by
reference U.S. patent application Ser. No. 14/065,857, filed Oct.
29, 2013, now U.S. Pat. No. 9,482,357, issued Nov. 1, 2016; U.S.
patent application Ser. No. 10/361,836, filed Feb. 10, 2003; and
U.S. Pat. No. 6,892,747. All of the foregoing patents and
applications are incorporated herein by reference.
Claims
The invention claimed is:
1. A thermally actuated valve for engagement to pressurized water
source, the valve comprising: a housing having an outer surface, a
near end and a removed end and having walls defining a fluid inlet,
the inlet for engaging a pressurized water source, and an outlet
and a valve seat between the inlet and outlet; a piston dimensioned
for receipt and location within the housing, the piston movable
between a first position engaging the valve seat and a second
position, disengaging the valve seat and permitting water from the
pressurized water source to flow between the inlet and the outlet;
a working material capable of moving the piston responsive to an
ambient temperature change; and a sleeve having an inner surface,
an outer surface, a first end and a second end for engaging the
outer surface of the housing; wherein the inner surface of the
sleeve has one or more channels each channel having a near end and
a removed end, the channels configured such that water leaving the
outlet of the housing flows through the channels and over at least
part of the outer surface of the housing and exits the sleeve at
the removed ends of the channels.
2. The valve of claim 1, wherein at least one of the channels has a
depth, when measured from the outer surface of the housing, of
between about 1.0-2.5 mm.
3. The valve of claim 1, wherein the number of channels is between
2 and 20.
4. The valve of claim 1, wherein the channels are defined by
multiple ribs on the inner surface of the sleeve.
5. The valve of claim 1, wherein the second end of the sleeve is
open and wherein the removed end of the housing extends beyond the
second end of the sleeve.
6. The valve of claim 1, wherein the outer surface of the housing
is cylindrical and the channels on the inner surface of the sleeve
are located circumferentially about cylindrical annulus between the
sleeve and the outer surface of the housing.
7. The valve of claim 1, wherein the housing is comprised of a
metallic material and the sleeve is comprised of a non-metallic
material.
8. The valve of claim 7, wherein the housing is brass and the
sleeve is plastic.
9. The valve of claim 1, wherein the first end of the sleeve is
configured to engage an outlet and the pressurized water source
includes an outside faucet.
10. The valve of claim 9, wherein the first end of the sleeve is
threaded and the outside faucet includes threaded male member.
11. The valve of claim 1, wherein at least one of the channels has
a depth, when measured from the outer surface of the housing, of
between about 0.1-2.5 mm and the number of channels is between 2
and 20.
12. The valve of claim 1, wherein the second end of the sleeve is
open and wherein the removed end of the housing extends beyond the
second end of the sleeve and the outer surface of the housing is
cylindrical and the channels on the inner surface of the sleeve are
coated circumferentially about an annulus between the sleeve and
the outer surface of the housing.
13. The valve of claim 1, wherein at least one of the channels has
a depth, when measured from the outer surface of the housing, of
between about 1.0-2.5 mm and the number of channels is between 2
and 20, the second end of the sleeve is open and wherein the
removed end of the housing extends beyond the second end of the
sleeve, and the outer surface of the housing is cylindrical and the
channels on the inner surface of the sleeve are located
circumferentially about an annulus between the sleeve and the outer
surface of the housing.
14. The valve of claim 13, wherein the housing is comprised of a
metallic material and the sleeve is comprised of a non-metallic
material.
15. The valve of claim 13, wherein the first end of the sleeve is
threaded and the outside faucet includes a threaded male
member.
16. The valve of claim 1, wherein at least one of the channels has
a depth, when measured from the outer surface of the housing, of
between about 1.0-2.5 mm and the number of channels is between 2
and 20, the second end of the sleeve is open and wherein the
removed end of the housing extends beyond the second end of the
sleeve, the outer surface of the housing is cylindrical and the
channels on the inner surface of the sleeve are located
circumferentially about an annulus between the sleeve and the outer
surface of the housing and the housing is comprised of a metallic
material and the sleeve is comprised of a non-metallic
material.
17. The valve of claim 16, wherein the first end of the sleeve is
configured to engage an outlet on the pressurized water source.
18. The valve of claim 16, wherein the first end of the sleeve is
threaded and the outside faucet includes a threaded male
member.
19. The valve of claim 1, wherein the cross-sectional area of a
channel is in the range of about 1.50 mm.sup.2 to 12.00
mm.sup.2.
20. The valve of claim 1, wherein the first end of the sleeve is
configured to engage an outlet and the pressurized water source
includes an outside faucet.
21. A thermally actuated valve for engagement to pressurized water
source comprising: a housing having an outer surface, a near end
and a removed end and having walls defining an inlet, the inlet for
engaging a pressurized water source, and an outlet and a valve seat
between the inlet and outlet; a piston for location within the
housing the piston movable between a first position engaging the
valve seat and a second position, disengaging the valve seat, and
permitting water from the pressurized water source to flow between
the inlet and the outlet; a working material capable of moving the
piston responsive to an ambient temperature change; and a sleeve
having an inner surface, an outer surface, a first end and a second
end for engaging the outer surface of the housing; wherein the
inner surface of the sleeve has multiple channels each having a
Near end and a removed end and is configured such that water
leaving the outlet of the housing flows through the channels and
over at least part of the outer surface of the housing and exits
the sleeve at the removed ends of the channels; wherein the first
end of the sleeve is configured to engage an outlet and the
pressurized water source includes an outside faucet; wherein the
channels are defined by multiple ribs on the inner surface of the
sleeve; and wherein the second end of the sleeve is open and
wherein the removed end of the housing extends beyond the second
end of the sleeve.
22. The valve of claim 21, wherein the cross-sectional area of a
channel is in the range of about 1.50 mm.sup.2 to 12.00
mm.sup.2.
23. The valve of claim 22, wherein the housing is metallic and the
sleeve is non-metallic.
24. The valve of claim 22, wherein the housing is brass and the
sleeve is plastic.
Description
FIELD OF THE INVENTION
Temperature controlled valve for water systems, including water
well and water softener freeze protection, as well as other system
water flow control.
BACKGROUND OF THE INVENTION
Water well and water softener systems use pressurized water in
pipes or other elements that are sometimes exposed to cold
temperatures. Freeze protection in the past has typically utilized
wrapping exposed elements with electrical heat tape or insulation
or a combination of both methods. While these solutions are often
satisfactory for most conditions, there exists a need for a
non-electrical, non-passive system that engages pressurized
elements of water supply assemblies for actively preventing
freeze-up by temperature, with the use of the pressurized systems
water, to purge the chilled water and subsequently, and as a direct
result of purging, replace with warmer water. This action prevents
the devices from freezing. There is also the need for flow control
in water systems wherein water cooler than ambient is needed
downstream of a water supply.
SUMMARY OF THE INVENTION
A water carrying pressure bearing system comprising a source of
water pressure is provided. Water bearing lines or water bearing
containers are sometimes exposed to external air temperature
fluctuations or ambient water conditions. Downstream of the source
of water, freeze protection is provided. Protected system elements
are in fluid communication with a water bearing line and the source
of water pressure. In the water bearing line, there is a purge
valve with a working fluid which may undergo a phase change, the
working fluid typically having a freezing point above 32.degree.
F., the valve in fluid communication with the water bearing line.
In one embodiment, the valve is biased to a normally closed
position at temperatures above the freezing point of the working
fluid. The valve opens as the working fluid contracts and freezes.
The working fluid may be, in one embodiment, selected from fluids
with freezing points being in the range of about 32.degree. F. to
about 50.degree. F. or preferably about 34.degree. F. to 45.degree.
F. The valve may have an outlet engaged therewith to carry away
water received therein when the valve opens responsive to cooling
air on an air sensing portion. The valve may be moderated by a
water temperature sensing side. The protected elements, in three
embodiments, comprise a water softener controller valve, a water
trough, and a pressure switch for any number of uses or
systems.
In a first embodiment of several, Applicant provides an active,
non-electrical, air and water temperature responsive purge valve
downstream of a well water pump and upstream of a pressure sensing
switch in a water distribution system, which may include a water
well and pressurized water tank. In a second embodiment, Applicant
provides a similar valve on a pressure line downstream of a water
softener. Fluid flow directly from the well pump, tank or other
pressure source may be about 56.degree. F. to 65.degree. F., no
matter the ambient temperatures. Purge valves in both embodiments
are typically located in outside air, where they may be subject to
contact with both the water in the system and the outside air. The
valve contains a chamber having a material selected from materials
which freeze between the temperatures of about 32.degree. F. and
50.degree. F., most preferably about 41.5.degree. F. In doing so,
the freezing working material contracts to allow a spring biased
valve to open on a water pressure line, which valve then dumps or
bypasses fluid from a high side (which may be well water pressure
tank pressure) to a low side bypass, which may be ambient pressure.
In doing so, pressure relief in the system at a temperature above
the freezing point of water, generates fluid flow from the well
and/or pressure tank or other source, thereby preventing freeze-up.
In a preferred embodiment of Applicant's valve, there is a range of
cross-sectional area ratios between water contacting elements of
the valve and air contacting elements of the valve.
In a valve having a body with a sealed working fluid chamber, a
bore and a valved fluid chamber having an inlet and outlet and a
seat between the inlet and the outlet, a piston for extending
through the bore from the working fluid chamber to the valved fluid
chamber. A spring is provided for biasing the piston and a working
fluid is provided for receipt in the working fluid chamber. The
working fluid is, in one embodiment, an alkane. An improvement
comprising a seal stack assembly is provided for engaging the
piston in the piston chamber between a working fluid chamber end
wall and a first end of the piston. The first end of the piston is
located in the working fluid chamber. A second end of the piston is
in the valved fluid chamber. The seal stack assembly comprises at
least one elastomeric element and one hard element, both elements
coupled to the piston such that the spring urges the second end of
the piston in the direction of the first end. The hard element may
be a washer with at least one slot in a side wall thereof.
A valve is provided having a body with a sealed working fluid
chamber, a bore and a valved fluid chamber. The valved fluid
chamber has an inlet and outlet and a seat between the inlet and
the outlet. A piston is provided for extending through the bore
from the working fluid chamber to the valved fluid chamber. A
spring is provided for biasing the piston away from the seat. A
working fluid is provided for receipt in the working fluid chamber.
A seal stack assembly is engaged, under compression, upon the
piston and in the working fluid chamber between a working fluid
chamber end wall and a first end of the piston. The first end of
the piston is typically located in the working fluid chamber and a
second end in the valved fluid chamber proximate the seat such that
temperature changes cause the piston to move responsive to
expansion and contraction of the working fluid between a seated and
an unseated position, the unseated position for the passage of a
fluid past the seat.
A thermally actuated valve is provided comprising: a housing having
walls defining an inlet adapted to receive water under pressure, an
outlet, a first chamber fluidly connecting the inlet to the outlet,
a second chamber having a near end and a removed end. Walls define
a bore separating the first chamber from the second, longitudinal
chamber. A resilient seat defines a seat plane, the seat for
engaging the housing, the seat adjacent the inlet of the first
chamber of the housing. A piston has a first end that includes a
nose and a second end and a longitudinal axis. The piston is
partially disposed in the first chamber, partially and slidably
disposed in the bore, and partially disposed in the second chamber.
The piston's longitudinal axis is aligned substantially
perpendicular to the seat plane. A spring engages the piston, so as
to bias the piston towards the removed end of the second chamber. A
seal stack assembly fluid seals between the piston and walls of the
second longitudinal chamber and is sandwiched under compression
between the spring and walls of the second chamber to prevent fluid
transfer between the first chamber and the second chamber. A
working material is sealed in the second chamber to move the piston
responsive to temperature changes between a seated position and an
unseated position.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1 and 2 are schematic illustrations of Applicant's novel
valve as used in a water well system and a water softener
system.
FIG. 1A is a schematic illustration of details of the relationship
between a mechanical purge valve and a pressure switch.
FIGS. 1B and 1C are illustrations of an electrical embodiment of
Applicant's purge valve for use in close proximity to a pressure
switch.
FIGS. 2A and 2B illustrate cross-sectional areas of a first, water
contacting portion and a second, air contacting portion,
respectively, of Applicant's novel valve.
FIGS. 3 and 4 illustrate side cross-sectional views of an example
embodiment of Applicant's novel valve in a closed and open
position, respectively.
FIGS. 3A and 3B are cross-sectional views (valve opened and valve
closed) of an alternate preferred embodiment of the purge valve in
which a stack assembly is used in the fluid compartment, rather
than O-rings 33a/33b in the piston rod channel or bore between the
fluid chamber of the working fluid and the water side.
FIG. 3C is an exploded view of a stack assembly for use in the
alternate preferred embodiment of the purge valve as set forth
herein.
FIG. 3D is an exploded perspective view of an alternate preferred
embodiment of a stack assembly.
FIG. 3E is a perspective view of an alternate preferred embodiment
of the stack assembly on a piston for use in a purge valve.
FIG. 4A is a cross-sectional detail view of the multi O-ring seal
of FIG. 4 showing the lubricant used therewith.
FIG. 5 is a side elevation cutaway of the purge valve (open).
FIGS. 6 and 6A illustrate the use of a remote purge port for pipe
downstream of the purge valve.
FIGS. 7A, 7B, and 7C provide cross-sectional cutaway views of
another example embodiment of Applicant's present mechanical purge
valve in three conditions: FIG. 7A, warming a water source
responsive to cool ambient temperatures; FIG. 7B, cooling a water
source responsive to warm ambient temperatures; and FIG. 7C, valve
closed condition, the valve not affecting the flow of water through
the system.
FIG. 8 is a partially schematic view of a cattle trough water flow
system that is adapted to use Applicant's novel valve in any of the
embodiments illustrated.
FIG. 9 is a cross-sectional view of a valve showing a method of
calibrating Applicant's mechanical valve so it opens and closes at
the proper temperatures.
FIGS. 10A, 10B, and 10C illustrate an alternate preferred
embodiment of Applicant's stack assembly, which may be referred to
as a "integral" one-piece stack assembly.
FIGS. 11A and 11B illustrate an alternate preferred embodiment of
the stack assembly.
FIGS. 12A, 12B, 12C, 12D, 12E, and 12F illustrate another
embodiment of Applicant's novel purge valve, this having a
sleeve.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 illustrates Applicant's purge valve 10 as part of a water
well assembly 100 and FIG. 2 illustrates Applicant's valve as part
of a water softener assembly 200. FIGS. 3, 4, and 4A illustrate
details of an example of purge valve 10 having a first body portion
30 and a second body portion 32, with a sealing area or piston bore
33 therebetween, and a valve seat 34. A temperature/pressure
responsive piston 38 opens a bypass port 36, and controls the flow
of water through the bypass port 36 when the temperature drops
below a set point, such as in the range of about 32.degree. F. to
50.degree. F., which set point is typically about 10.degree. above
the freezing point of water. Piston 38 is responsive to a change in
volume (at phase change) of a working fluid 40, which working fluid
fills a fluid chamber 42 in the first body portion 30 of the valve.
When working fluid 40 (which is typically not water based) in
chamber 42 reaches a point, it will contract as it loses heat and
changes phase from a liquid to a solid at the freezing point of the
fluid, and will cause piston 38, biased open by a spring 44, to
retract from valve seat 34. This allows water well and/or pressure
tank pressurized water to flow through the bypass port 36 and out
an outlet or purge port 37. Further details of Applicant's novel
valve will be set forth after an explanation of its use in the
system.
Turning to FIG. 1, it is seen that system 100 may include a water
well 112, such as a domestic or commercial (municipal) water well,
which may have a pump 114 (mechanical or electrical), such as
submerged pump or any other pump suitably located to draw water
from below the ground level of the well. A water supply line 115
provides the water under pressure through a pressure switch 120, to
a pressurized water tank 116. Demand from users downstream of
pressure tank 116 will allow water to flow out through line 118 to
provide their needs. Pressure switch 120 is typically provided
somewhere in the system (typically at, or upstream of pressure tank
116), responsive to pressure changes in tank 116, such that below a
low set pressure, pump 114 will be activated and provide water to
tank 116, and above a high set pressure, will shut off.
FIG. 1 illustrates Applicant's well water well assembly 100
providing various downstream water uses of the water from the water
well assembly 100. These uses may include use in a commercial or
residential structure 216, in a cooling tower, such as those known
in the art for cooling the hot side of air conditioners 218, and a
livestock animal trough 220, as set forth in more detail
hereinbelow.
Pressure switch 120 may be of the diaphragm type and when exposed
to temperatures near or below 32.degree. F., especially when windy,
can freeze up faster than any other part of the well assembly. They
then become non-responsive to pressure changes in the system. When
this occurs, a pressure drop in the pressure tank will not initiate
a signal to start the pump, and the system has failed mechanically
and is subject to further freezing and potential damage to
equipment.
Use of Applicant's purge valve 10 in the system, typically at or
upstream of tank 116 and typically close to the pressure switch,
will help ensure that under even severe weather conditions, the
purge valve, acting independently of the pressure switch, will help
prevent freeze-up.
Applicant's water well assembly may have pump 114 which may be a
mechanical water pump, such as a mechanical or a sucker rod pump or
an electrical pump (or any other suitable pump). It may have a
storage tank, which may be a pressurized storage tank, gravity feed
storage tank or any suitable water storage tank for receiving water
pumped from a domestic, commercial or agricultural water well.
Typically, one or more water flow control devices are a part of the
water well assembly to control the water pumped as it is used by
downstream elements of the water well assembly.
FIG. 1A illustrates a schematic detail view showing the manner in
which Applicant's purge valve 10 may be used with a fluid pressure
source pressurizing a pressure switch.
In FIG. 1A, a pressure switch 120 as known in the art, may include
diaphragm 120a responsive to water pressure in pressure switch
mount pipe 121, may engage one arm of electrical contacts 120b to
close or open the contacts and energize/de-energize a remote pump
responsive to water pressure in a pressure source and responsive in
some embodiments to pressure in a pressure tank as set forth
herein. A tee or horizontal member 122 may extend perpendicular to
the typically vertical pressure switch mount pipe 121. In any case,
Applicant's purge valve 10 is typically located below the pressure
switch 120 and in a manner that it may open and gravity drain, for
example, through purge port 37, fluid from contact with the
diaphragm. This will prevent freeze-up from damaging the diaphragm.
It will also initiate a pump "on" condition by draining some water
from tank 116. The pump will re-pressurize the system with,
typically warmer water which, in turn, will help shut the purge
valve 10. It will also initiate an "on" condition, by draining
water from the pressure tank, which forces the pressure switch to
turn the water well pump on, and refill the tank and piping with
warmer water.
FIG. 1A illustrates that, in one embodiment, purge valve 10 is
usually within a minimum distance (measured by fluid pathway) of
about 1/4 inch to about 12 inches from the diaphragm of the
pressure switch. This will help protect and prevent freeze-up of
the pressure switch.
FIGS. 1B and 1C illustrate an alternate preferred embodiment of
Applicant's system. Wherein the other systems set forth herein use
a mechanical purge valve 10, it is noted that, in conjunction with
a pressure switch, a solenoid purge valve 126 powered by a power
circuit 127 may be used in close proximity to the pressure switch
so that it may drain from a gravity fed outlet 128, water or other
fluid at a pressure source 121. That is to say, instead of a
mechanical valve 10, a solenoid valve 126 may operate with a
circuit which includes power 123 (battery, DC, AC, solar or any
suitable source) and a thermostat switch 130. Thermostat switch 130
will typically be set for the same approximate range as the
mechanical purge valve, that is closing at least several degrees
above freezing and opening solenoid valve 126 to allow fluid to
drain before freeze-up at the pressure switch. As seen in FIG. 1C,
thermostat switch 130 (or a sensor therefor) may be placed adjacent
or on elements, metallic or non-metallic, downstream of solenoid
valve 126. At position 2 or 3 as seen in FIG. 1C, when warmer water
from a well, for example, flows through an open the solenoid valve,
thermostat switch 130 may open causing the solenoid valve to close,
thus re-pressurizing the pressure switch with, typically, warmer
water. Position 1, FIG. 1C, locates switch 130 in air, while
positions 2 and 3 are both water and air temperature exposures.
Further details of purge valve 10 may be appreciated with reference
to FIG. 3. First portion 30 may be referred to as "air exposed"
portion and contains an external surface, typically cylindrical and
constructed of brass or other suitable metal, which also may be
referred to as the air temperature sensing portion of purge valve
10. A second portion 32 has an interior that may be subject to the
presence of stationary water (or empty) when the valve is closed
and which carries water in an open or "protect" mode and is subject
to the temperature bias of the purged water as it is discharged. In
an alternate preferred embodiment, the body defined by elements
30/32/33 may be made of plastic, such as Delrin.RTM..
In a situation where the air temperature cools suddenly, for
example, with the passage of a sudden cold front, first portion 30
will cool more quickly, subject as it is to exposure with the air,
especially moving air, and second portion 32 will lag, subject to
the water or proximity to system water and the contact with the
water within (valve open) body portion 32 or proximate (valve
closed) to body portion 32. Water is known to moderate temperature
changes (it has a much higher specific heat than the material,
typically brass or other suitable metal, of which the valve body is
made). Warm water within portion 32 will typically provide warmth
to portion 32, which by conduction will provide some heat to
portion 30 as it drops below the set point. Thus, portion 32 will
have the effect of moderating air caused temperature changes of
portion 30, so that especially with sudden changes of air
temperature, sufficient heat may flow from portion 32 to 30 to
moderate and prevent too quick a freeze-up of working fluid 40 (and
thus a draining of water from the system).
FIGS. 3 and 4 illustrate purge valve 10 in a closed and open
position irrespectively. Working fluid chamber 42 is sealed at a
first end by removable threaded cap 20. Cap 20 may use an O-ring 22
on a shoulder thereof to tightly seal working fluid 40 in fluid
chamber 42. Typically, the working fluid will be sealed into the
chamber when in its liquid phase. The set point is calibrated by
advancing the plug until the nose 38a of piston 38 is sealed in
seat 34 which, in one embodiment, is an O-ring (see also FIG. 9).
Spring 44 biases valve piston to the open position (see FIG. 4).
However, fluid pressure of working fluid 40 in fluid chamber 42
holds the valve in the seated or closed position at temperatures
above the set point. At these temperatures, the working fluid will
expand slightly (compared to set point) to maintain a good seat,
especially in an elastomeric seat, such as valve seat 34. However,
as the air temperature cools through the set point, the working
fluid will begin to undergo phase change and contract, thereby
temperature proportionally opening valve as in FIG. 4. This will
allow water to pass into the valve and out the port, utilizing the
ambient pressure PW (see FIG. 3), which pressure is generated by
the pressure tank and/or pump.
FIGS. 4 and 4A illustrate the use of an anti-seize lubricant 33c,
which has a freezing point less than water. These lubricants may be
used to fill in, around, and between the O-rings that separate the
chamber containing the working fluid and the chamber through which
purged fluid, typically water, will pass out of when the purge
valve is opened. Tolerances between the piston and the body may be
plus or minus 0.001 inch. It is seen the lubricant tends to be held
in between the spaces that separate adjacent O-rings and the piston
walls where they contact the body.
When the purge valve opens, water will be drawn through the
channels of second body portion 32 and out the drain port to dump
onto the ground, to recycle in the well (as illustrated in FIG. 1)
or for other suitable disposal. This water will typically be warmer
than air temperature and will warm the surrounding material of
portion 32. Heat by conduction will flow to portion 30.
Working fluid 40, in certain embodiments, will undergo a phase
change at about 41.5.degree. F. (5.5.degree. C.), which is
approximately 10 degrees above the Fahrenheit freezing point for
pure water. One such material is an alkane known as Tetradecane
(C.sub.14H.sub.30), which undergoes a volumetric contraction of
about 20% at the freezing/melting point (range 39-43.degree. F.) as
measured from a liquid phase to a solid phase. Preferably, working
fluid 40 would undergo a phase change from liquid to solid
contracting at the phase change, which freezing (melting) point is
in the range of about 6.degree. to about 18.degree. F. above the
freezing point of water in one embodiment.
In some embodiments, cross-sectional area .alpha. of second body
portion 32 is typically larger than cross-sectional area .beta. of
first body portion 30 (see FIGS. 2A and 2B). The metallic or
plastic elements defining the body of the valve may, in particular
embodiments, be brass (specific heat of approximately 0.1). The
range of the larger area, that is, the cross-sectional area of
second body portion 32 which contacts the water may be in the range
of 1.2 to 4 times the cross-sectioned area of the air sensitive
first body portion 30.
Turning to FIGS. 2, 6, and 6A, a water softener system 200 is
illustrated, which has a water softener pressurized on a
pressurized water source 210, which may be water well or water
pressure tank or city water. FIGS. 6 and 6A illustrate Applicant's
use of purge valve 10 on a water softener assembly 200 downstream
of a water softener tank 214. Water from water softener tank 214 is
pressurized, and purge valve 10 is typically exposed to ambient
conditions. Pipes 212 downstream of tank 214, and other elements of
the system may be exposed to cold air, as in a garage, shed or
outside of a building. As such, they may benefit from use of
Applicant's purge valve 10, which may be "teed" or otherwise
installed into a water pressure bearing outlet, such as soft water
outlet line 211, that is subject to cold temperatures. In the same
fashion as set forth with the water well assembly 100, cold air
temperatures will generate purging of the pressurized lines, which
flow will maintain the circuit in a flow condition, for a period of
time, to prevent freeze-up. The use of Applicant's valve is an
alternative to leaving faucets on inside the house (so as to keep
water flowing in system), which can waste water if ambient
temperatures are above freezing and may let pipes freeze if the
faucet discharge is less than what is needed for very cold
temperatures. The use of Applicant's purge valve 10 in either
assembly will reduce such water wastage, while preventing the
assembly from freezing.
FIG. 5 illustrates the use of a vacuum break 46 in a threaded drain
fitting 47, which will help prevent siphoning when the removed end
of a drain tube 48 has water in it. Vacuum break 46 will also
provide a water outlet, should any portions of drain line 48 freeze
up. Drain tubes 48 are typically placed so that the removed end
thereof is adjacent to a drain or goes back into the well.
FIG. 5 also illustrates the use of a sleeve or jacket 50, which is
typically shaped with an open end 52 and a body 54, and a closed
end 55, that will slip on and snugly engage the exterior portion 30
to act as a shield and insulation from the possibilities of wind,
sleet, snow, ice and/or their accumulation, from affecting the air
temperature sensitive second body portion 30 of purge valve 10.
Such an insulation jacket 50 may be made from 1/10 inch pliable
plastic or suitable material typically with a thermal conductivity
less than metal, or may be an air gap.
In FIGS. 3, 4, and 4A, it is seen that working fluid 40 is sealed
in fluid chamber 42 by cap 20 at one end. Sealing area or bore 33
may have multiple O-rings 33a/33b in grooves, which O-rings are
urged against the outer wall of piston 38. One system of O-rings or
other elastic material that has proved to be an effective seal to
maintain the working fluid sealed in and to resist the pressure
generated by expansion of the working fluid may be found in U.S.
patent application Ser. No. 11/275,135, which is incorporated
herein by reference.
Purge valve 10 may be placed on a water well close to the pressure
switch, approximately 1/4'' to 12'' from the pressure switch in
certain embodiments. The purge valve may be placed on or near the
water softener control box or downstream of the water softener. In
general, Applicant's novel purge valve may be used anywhere on any
system where there is a need to prevent freeze-up of pipes.
Turning to FIGS. 3, 4, and 5, basically, the following summarizes
some of the structure and functionality of the valve:
First body portion 30: Cylindrical, typically metallic, defines an
inner chamber External surface exposed to ambient air; internal
containing chamber 42 which contains the working fluid and removed
end 38b of piston 38 Sealing plug or cap 20 for sealing working
fluid and pressure calibration (typically screw) Spring 44 to bias
"open" Optional jacket or sleeve (see FIG. 5) for exterior of
metallic cylinder
Second body portion 32: May take any external or internal
configuration within an internal water cavity/chamber 31 Chamber 31
bordered longitudinally with sealing area (see below), and bypass
port 36, and also containing a vertical trending purge port 37
Metallic heat flow path between (among) T.sub.1 of water in chamber
31, T.sub.2 in cylinder (working fluid 40) first body portion 30,
and T.sub.3 (air) on exterior surface of second body portion 32
(see FIG. 4)
Sealing area or bore 33, located longitudinally between body
portions 30 and 32 (see FIG. 4) for locating piston 38 Multiple
seals adapted to withstand pressure in system Seals on both sides
of a leak vent 39 (prevent leakage) typically lubricant filled
(prevents moisture and debris accumulation) O-rings 33a on working
fluid side prevent leakage of the working fluid O-rings 33b on
water side prevents leakage of water into a leak vent 39 Use of an
anti-seize/lubricant compound 33c (FIG. 4A), on and around the
O-rings is preferably food/drug grade
FIG. 3 shows purge valve 10 in the closed position. However, purge
valve 10 in the closed position may have nose 38a of the piston
past valve seat 34, that is to the right of the position of the
nose with respect to the valve seat as seen in FIG. 3--such that in
a closed position, the O-ring or other element defining valve seat
34 is on the cylindrical body portion of the piston. Regarding the
valve seat, it may be an O-ring or other suitable elastomeric
material. Regarding the O-rings 33a/33b or other sealing members of
bore 33, they are made of an elastomeric material that does not
dissolve or react with the working fluid, but provides an effective
fluid seal against the body of the piston. Anti-seize/lubricant
compound 33c, such as a food grade silicon-based composition, may
be used on and around the piston/O-ring interface. FIG. 4A
illustrates the use of a low temperature (below the freezing point
of water), anti-seize/lubricant compound 33c around and between the
multiple O-rings 33a/33b that the piston moves over.
Turning to FIGS. 5, 6, and 6A, an optional purge port tube 56 may
be provided to remotely locate a removed end 56a from a near end
56b. Near end 56b is engaged with a fluid tight couple to the purge
valve inlet. When purge valve 10 is in a closed position, the water
softener, well water or other pressure source is in a normal
(non-freezing environmental) condition, with the purge valve and
all elements thereof "invisible" to the system. However, when the
air temperature gets cold outside and first body portion 30
communicates a temperature drop by cooling the working fluid to
freezing, the valve will then open and drain fluids out through
bypass port 36 and purge port 37 and/or external drain tube 48.
However, because of the use of purge port tube 56 placed in an
annulus of pipe DS downstream of valve 10 and engaging the inlet of
the second body portion 32, some of the purged fluid is being drawn
from the remote removed end 56a and, therefore, flows all the way
through the annulus between the tube 56 and the inner walls of the
DS pipe purging it of cooling water and generating flow, with
warmer fluid coming in and preventing freeze-up. Note that removed
end 56a is typically located past where the pipe annulus enters the
interior environment, whether that be just below ground or just
inside a wall (see FIG. 6 or ghosted lines, FIG. 6A). In either
case, the effect of using purge port tube 56 with removed end 56a
located in a warmer non-ambient, non-outside air temperature
environment is to maintain flow through all of the pipe annulus,
even portions downstream of the purge port during cold weather.
Arrows at A in FIG. 6A show flow of water when the valve gets cold
and opens (piston and seat omitted).
FIGS. 7A, 7B, and 7C illustrate an alternate embodiment 10' of
Applicant's valve. Structurally, the difference in the previous
embodiment (see, for example, FIGS. 3 and 4) lies in the structure
of piston 138. In the alternate embodiment 10' of the valve, piston
138 is seen to have a nose 138a, which has an annular recess 141.
The annular recess is dimensioned such that in a "valve warm"
condition (FIG. 7B), wherein expansion of the working fluid 40 in
chamber 42 has, through expansion responsive to the warm
air/ambient water temperatures, pushed the tip of nose 138a past
O-ring or valve seat 34, so that annular recess 141 is adjacent to
the seat. This is the condition seen in FIG. 7B and it may be seen
that cool fluid (relative to air temperature) may pass through the
space created by the annular recess and out purge port 37 to
provide water from the well or storage, which will typically be
cooler, to elements downstream of drain port 37. In this manner,
Applicant's alternate embodiment 10' acts to provide cool fluid,
that is, cooler than air/ambient water temperature, to elements
downstream of the valve. Embodiment 10' will also prevent freeze-up
(see FIG. 7A) in the manner of valve 10.
Applicant has found that, in the summer, livestock, while thirsty
and in need of water, are reluctant to drink water from a trough
when the water in the trough is too warm. What Applicant provides
therefor in an alternate embodiment 10' of the valve is the ability
of the valve piston to "overshoot" the seat and place the annular
recess 141 adjacent the seat and allow cooler water from tank 304
to flow into trough 306. Water in the tank 304 is typically cooler
in the summer than the surrounding air temperature and the water
temperature in the trough, and warmer in the winter than the
surrounding air temperature and temperature of the trough,
containing as it is, a large warm water received from the
ground.
FIG. 8 illustrates a use of Applicant's alternate embodiment 10' in
a livestock watering system 300. Livestock watering systems are
used to provide water for livestock in pastures and feedlots and
may comprise a water pump 302 engaging a water well 303. Water pump
302 may be a windmill using a mechanical pump as well known in the
art of windmill water pumping. Pump 302 may also be electrical. As
illustrated in FIG. 8, pump 302 may pump water from well 303 into
an elevated tank or other water tank 304 (pressurized or gravity
feed) for selectively supplying water to a nearby trough 306. A
conduit 308 is typically provided with Applicant's valve, in either
embodiment, but in the embodiment illustrated 10' at the removed
end of conduit 308 and typically beneath water level WL of trough
306. In some cases, a parallel water feed system 310 may be
provided to bring water to trough 306 responsive to water level or
float valve 312. Such float valve 312 controlled water level
systems are well known in the art. Applicant's system provides
water to trough 306 separate from and not controlled by the float
valve system, if one is present.
As is seen in FIG. 8, first body portion 30 and, in fact, the
entire purge valve 10 or 10' may be submerged below typical water
levels in the trough. However, the valve might be in air positioned
so it drains water into the trough when opened. As seen in FIGS.
7A-7C, Applicant's valve 10' is adapted to provide water that is
cooler or warmer than a preselected water temperature range.
Typically, the water in the trough has a greater surface area
exposed to cold or warm air temperatures than the larger volume of
water in tank 304 and thus will reach a cooler or warmer
temperature sooner than the storage tank in the same air
temperature, humidity, and wind conditions. Thus, the valve open
condition of FIG. 7A, which typically occurs at temperatures up to
about 18.degree. F. above the freezing point of water, will open
and allow relatively warmer water from the tank 304 to enter the
trough to prevent ice buildup when the air temperature is cool.
When the air gets warm, it can warm the trough water and a
condition as seen in FIG. 7B can result. This will allow cooler
water to flow into the trough.
FIG. 9 illustrates threadably removable cap 20 adapted to engage
the removed end of second body portion 32, so as to seal fluid
chamber 42. Cap 20 may have a recessed tool receiving section 20a
on an exterior surface thereof, and an annular recess 23 on the
near end thereof for holding an O-ring 22 (see also FIG. 3).
FIG. 9 also illustrates a method of calibrating the piston so that
it seats and unseats at the proper temperatures. In this method,
the valve housing is held vertically in a fixed position and the
working fluid, liquid at room temperature, is used to fill fluid
chamber 42. At this point, the spring will have the piston fully
retracted (see FIG. 4). In this method, the valve housing is
typically held vertically in a fixed position and the working,
liquid at room temperature, is used to fill the fluid chamber 42.
At this point, the spring will have the piston fully retracted from
the seat (see FIG. 4, for example). The spring is not under
compression, the cap is off, and the fluid chamber is fully filled.
The cap (which may be self-tapping) is then threaded in with rotor
tool 317 until the O-ring 22 contacts the inner walls of the fluid
chamber. Further rotation of the cap compresses the working fluid,
then moves nose 38 until it is against a dial indicator gauge/limit
switch 315 and/or limit switch. The dial indicator gauge/limit
switch actuates to turn off the rotary tool 317 when the nose, at
room temperature, has moved to the preselected position past the
seat as indicated in FIG. 9. Further warming will simply move the
nose slightly further down, as seen in FIG. 9, but the dial
indicator gauge and/or limit switch 315 has properly positioned the
nose with respect to the seat, such that the valve will unseat when
the first set temperature, typically the freezing point or freezing
range of the working material, is reached, opening the valve as
seen in FIG. 4 or 7A.
The combination of a pressure switch with Applicant's mechanical or
electrical purge valve in close proximity thereto, may be used in
any suitable environment where the pressure switch may be exposed
to ambient freezing conditions. Exemplary of these environments are
the following: water wells, reverse osmosis systems, ice machines,
water level controls (depth gauges and large tanks), aerobic septic
systems, lawn sprinkler systems, fire sprinkler systems, geothermal
AC systems, cooling tower AC systems, and gray water distribution
systems. While the 0 to about 12 inches is measured typically from
the diaphragm surface along the water path to the inlet of valve 10
or solenoid 126, other distances may be suitable, including
preferably between about 2 to about 8 inches.
There are many instances where a valve that opens in response to a
change in temperature allowing water flow is beneficial. One such
instance is the protection of water pipes from freezing. Another
instance is the freeze prevention of livestock drinking troughs
that are subject to freezing conditions. In some cases, it is
useful to use a fluid with a phase change melting point at the
desired valve actuation temperature. Alkane paraffins may be
commonly used, as they exhibit a large change in volume at their
respective melting points and there are many to choose from.
One useful alkane that may be used in the construction of automatic
water valves for freeze prevention is N-tetradecane with a melting
point of 42.degree. F. (4.degree. C.), that is, above the freezing
point of water. This freezing point may be lowered as desired by
the addition of a suitable "antifreeze" such as N-dodecane.
In one embodiment, an alkane working fluid is contained in a
chamber closed by a moveable piston rod at one end. As the alkane
freezes, it contracts, allowing the piston to be urged by spring
pressure to slide and open a water valve seat that is constructed
at the other end of the piston rod. Upon warming, the alkane melts
and expands sliding the piston rod against spring pressure to close
the water valve seat.
For this device to be constructed, a slideable seal or stack
assembly allowing movement of the piston rod but effectively
separating the alkane working fluid from the water may be useful.
Also a means of supporting the piston rod may be useful.
An object of the following embodiment is to provide a seal in the
form of a stack assembly for the piston rod in a temperature
responsive valve. With a stack assembly, sealing area or bore 33
typically no longer uses "O" rings 33a/33b (see FIG. 4), the
sealing function being provided by the stack assembly located in
the first body portion 30.
FIGS. 3A, 3B, and 3C illustrate an O-ring/washer seal stack
assembly (hereinafter sometimes "stack assembly") 400 (Fig. C) and
400' (Figs. A and B). It typically comprises multiple alternating
washers and O-rings for engagement upon a piston as set forth
hereinbelow for providing, among other things, the O-rings for
sealing against the passage of fluid past them and the washers or
disks for helping compress the O-rings and for helping to locate
the piston, and further for acting as a wiper with its inner
diameter on the outer diameter of the piston.
FIG. 3C illustrates a stack assembly 400 comprising, from left to
right, washer 402, O-ring 410, washer 404, O-ring 412, washer 406,
O-ring 414, washer 408, and O-ring 416. The O-rings on either end,
here O-rings 410/416, may sometimes be viewed as "primary" O-rings
in that, in the manner of use as set forth more specifically below,
O-ring 410 will seal against the passage of a pressurized fluid on
its left from migrating across the O-ring to the right (see FIGS.
3A and 3B), for example, a fluid "A." At the other end of the
stack, O-ring 416 may seal against the passage of a fluid on its
right, say fluid "B," from migrating past it and moving to the left
as seen in FIG. 3C. That is to say, stack assembly 400 may be used,
in one embodiment, to assist in the prevention of a migration of
fluids across the O-rings on either end. For example, when one
fluid on the left of the O-ring to the left of the stack and a
fluid on the right to the O-ring on the right end of the stack,
these primary 410/416 or end placed O-rings will help prevent
migration of fluid either way, but will be primary to the fluids
outside of them (fluid to the left on element 410, FIG. 3C, and to
the right of O-ring 416, FIG. 3C).
The primary, end placed O-rings 410/416 may be separated from, with
washers (404/406/408, FIG. 3C; 404/406/408, FIG. 3B), one or more
intermediate or backup O-rings (see 412 and 414, FIG. 3C; 412,
FIGS. 3A and 3B). These backup or intermediate O-rings may be
between the end placed O-rings and typically separated therefrom by
washers. These are backup in the sense that, if the primary O-rings
perform properly, they will maintain a fluid tight seal. However,
should there be any leakage past the primary O-rings, the backup
O-rings should prevent leakage either way, left or right, if there
is leakage on either primary or end placed O-ring.
FIGS. 3D and 3E illustrate an alternate preferred embodiment of
stack assembly 400', here comprising, between the primary O-rings
410/416, a slotted washer/unslotted washer pair 407/408, which
slotted washer/unslotted washer combination 407/408 includes one
slotted washer 407 with slots 407a (see FIG. 3D). Slots 407a are
radially cut partly into one or both side walls between the inner
diameter and the outer diameter. The function of the slots is to
help allow the passage (should either primary O-ring leak) to
assist in the passage of a fluid through the stack assembly for,
preferably, flow out of vent 39 (see FIGS. 3A, 3B, and 4). This
vent helps prevent the fluids from mixing.
For example, FIGS. 3A and 3B both illustrate a valve having the
slotted washer/non-slotted washer 407/408 combination, that is,
stack assembly 400'. Turning to FIG. 3A, it may be seen that, if,
for example, water on the right side of O-ring 414 leaks through
O-ring 414, it will, in squeezing past washer 408, work its way
through slot or slots 407a in washer 407 and will find the easiest
passage is out leak vent 39, rather than past either O-ring 410 or
412. Likewise, as seen in FIG. 3B, tetradecane 40 or other working
fluid in fluid chamber 42 where the stack assembly is located may
bypass O-ring 410, if O-ring 410 is faulty and backup O-ring 412 is
faulty, but will then more easily work its way out vent 39. This
helps avoid contamination across pressure zones separating
different fluids in the event that there may be O-ring failure. In
addition, the washers at their inner diameters tend to act as
wipers on the outer surface of piston 38 as the piston, responsive
to volumetric changes in the fluid chamber of the fluid, moves to
the left and right between opened and closed positions.
Turning back to FIGS. 3A and 3B, one may see that working fluid is
located in a fluid chamber, which fluid chamber is substantially
defined by the space to the left bore 419, the bore bearing part of
piston 38, which has one end in the working fluid chamber, and the
other end in the valved fluid chamber (see also FIG. 11B).
Moreover, it is seen that washer 402, the first washer to the left
of O-ring 410, acts not only to help locate O-ring 410, but to seat
the removed or right end of spring 44. This may be compared to FIG.
3 or 4 above in which spring 44 simply seats to the end of chamber
42. Indeed, FIGS. 3 and 4 compared to FIGS. 3A and 3B indicate that
the O-ring sets 33a/33b as seen in FIG. 3, which perform sealing
functions to separate water and tetradecane, may be removed and
replaced as seen in FIGS. 3A and 3B with a single stack 400 or 400'
(slotted), in which there are at least two end or primary O-rings,
here 410/414, which are spaced to either side of vent 39 and, in
one embodiment, a vented set of washers, here slotted 407/unslotted
408, adjacent vent 39, so as to help any leaked fluid bypassing
either primary O-ring into vent 39.
The use of Applicant's seal stock eliminates a machining step, that
of machine the grooves for O-ring sets 33a/33b in FIG. 4. Indeed,
there are no O-ring grooves in FIGS. 3A and 3B, the O-rings acting
as part of a stack and located in the fluid chamber. "Effective"
fluid chamber may be deemed by length 442 (where the fluid meets
the first O-ring), but the machined fluid chamber, which carries
the spring acting on the piston end and the stack assembly
400/400', which in turn acts on the removed end of the machined
fluid chamber 42, extends past vent 39, vent 39 being isolated on
the alkane side by at least primary O-ring 410 and back up 412, and
on the water side by at least primary O-ring 414.
The inner diameter of a washer may be greater by about 4 mil (about
2 mil per side) when compared to the OD of the piston. The outer
diameter of the washer may be about 2 mil less than the inner
diameter of the working fluid chamber (about 1 mil per side). The
O-ring inner diameter compared to the piston outer diameter may be
greater by about 6 to 8 mil (about 3 to 4 mil per side).
The environment in which the stack assembly may be used is any
environment in which O-rings are used in conjunction with a piston
to separate different fluids under pressure. One such environment
is that of the freeze plug as used in the figures set forth
elsewhere in this application.
FIGS. 10A, B and C illustrate an integrated rod seal 400'' in which
the multiplicity of ribs 420/422/424/426 are interspersed with a
multiplicity of spacers 428/430/432, the ribs and spacers integral
with one another and coupled to the piston (see FIG. 10C).
By integral or one-piece means that, unlike the previous
embodiments, where there were separate O-rings and washers--instead
there are elastomeric protrusions 420/422/424/426 which are
connected by an integral width-wise spacer elements 428/430/432.
The protruding elements may be elastomeric and may be ribs and the
entire structure may be molded in one piece of elastomeric
material, such as rubber or rubberlike material having, in one
embodiment, a hardness of durometer of about 80 to 90. As seen in
FIG. 10C, a protective washer 431 may be used between the
sleeve-like integral stack 400', which is entrained upon the
piston. As can be seen in FIG. 10C, there are still primary rib
elements, one the rib all the way to the left (420) and all the way
to the right (426) and at least one secondary rib (two in FIG. 10A,
one in FIG. 10C).
In one embodiment, the material is molded and about 80-90
durometer. Ribs extend both outward and inward like a stack of
O-rings integrated or glued together. The multiple ribs of the one
piece seal 400'' may wipe the rod multiple times with a minimum of
drag. Drag is often a problem with sealing. Wall clearance may be
about 0.005 inches per side, inside and outside the groove on the
spaces between the raised ribs.
Seal stack assembly 400/400'/400'' is useful as a seal in various
valves, including those set forth in this application, and may
consist of, in one embodiment, at least three elements:
1. At least one elastomeric element, such as an O-ring or other
flexible seal;
2. At least one hard washer of plastic or metal close fitting
between the bore of a chamber and the outer diameter of a piston
rod;
3. A spring to compress the seal stack.
Multiple elastomeric elements may be stacked, alternately, with
hard elements as necessary, each performing specific function, such
as to provide:
1. Sealing from leakage or contamination between a working fluid
chamber and outside environment consisting of water at
atmosphere;
2. Redundant sealing to provide backup for number 1 above;
3. Wiping of the rod to help ensure debris does not damage sealing
O-rings.
Hard washers (such as nylon, Delrin.RTM. or Teflon.RTM.) may be
inserted between elastomeric elements as required to provide:
1. Centering of piston OD (outer diameter) in chamber bore;
2. Distribute spring pressure compressing the stack; and
3. Provide two point support for piston rod to help keep it
centered;
4. Additional scraping and wiping of rod by the hard washers will
ensure debris cannot damage sealing O-rings.
FIGS. 11A and 11B illustrate in an alternate preferred embodiment
useful for temperature responsive valves, a machined body 500 that
may include a working fluid chamber 502 for containing a piston 508
and spring 510. FIGS. 11A and 11B illustrate machined body 500 in
which there is a working fluid chamber 502, the working fluid
chamber 502 containing piston 508 and a spring 510 as in other
embodiments illustrated herein. An end cap 512 and O-ring 514 may
contain a working fluid, such as tetradecane or other alcane, here
designated fluid "A", from a separate fluid "B," which may be, in
one embodiment, water. Piston 508 is seen to comprise two sections
508a/508b, section 508b having a smaller diameter where it engages
section 508a. Captured O-ring 506 is captured in a groove machined
in body 500, unlike the O-rings of the stack assemblies set forth
herein which ride in the chamber for the working fluid. Moreover,
it is seen in the valve opened position (FIG. 11A), O-ring 522 is a
primary O-ring, as fluid will bypass O-ring 506, as O-ring 506 in
the valve opened position is slightly spaced apart from the outer
diameter of section 508b of the piston. However, in a piston closed
position (FIG. 11B), O-ring 506 is sealing against leakage of fluid
B from right to left as seen in FIG. 11B. In either valve opened or
valve closed position, O-ring 520 of stack assembly 504 is the
primary O-ring to the left in the valve closed or valve opened
positions while maintaining a seal to keep fluid A, in one
embodiment, tetradecane, to the left of the O-ring.
A bore 519 is provided between working fluid chamber 502 having a
working fluid such as tetradecane and valved chamber 521 which may
contain a valved fluid such as Fluid "B." The spring is entrained
on a first end of the piston, for example, the first end of the
piston in the working fluid chamber and up against the stack
assembly 504. Stack assembly 504 may include a primary O-ring 520
and a secondary O-ring 522, which may be flush against a bore end
of the working fluid chamber. Washers 516 and 518 are provided
first washer 516 for seating the spring thereto. Spring 510 urges
stack assembly 504 against the bore end wall of the working chamber
as illustrated and temperature and phase change of a working fluid
such as tetradecane causes the piston to move to the right
(warming, expanding, FIG. 11B) or to the left (cooling,
contracting, FIG. 11A). In the operation of valve shown in FIGS.
11A and 11B, it is seen that when the valve is closed bore mounted
O-ring 506 acts a primary for the movement of any fluid therepast
(from right to left as seen in FIG. 11B). On the other hand, when
the valve is open as seen in FIG. 11A, and stack O-ring 522 is a
primary, O-ring 520 is a second primary and there is no secondary
in between.
Any parts of the valve may be made of plastic or metal, in one
embodiment, the piston is metal, for example, stainless steel or
copper, to enhance thermal conductivity. In another embodiment, the
housing comprising the body portions or any other parts disclosed
herein may be made of tough, durable plastic, such as an acetal
plastic (such as Delrin.RTM.).
FIGS. 12A, 12B, 12C, and 12D illustrate another embodiment of
Applicant's novel purge valve 10. Purge valve 10 has a purge valve
body 11 comprising a first body portion (or lower portion) 30 and a
second body portion (or upper body portion) 32 (see FIG. 12B). The
internal structure and function of the valve is identical to that
in the disclosure herein. However, valve body 11 may also include
an upper lip 41 as seen in FIG. 12B. Structurally, sleeve 650 is
seen to partially enclose valve body 11. Functionally, sleeve 650
is provided to engage valve body 11 to a standard exterior faucet
EF (see FIG. 12D) and, further, to direct fluid flow coming from
the outlet of the faucet through purge port 37 (or purge ports), in
a controlled manner to channel the fluid coming out of purge
port(s) so it stays in contact with the exterior or first body
portion 30. The sleeve 650 may be compared to sleeve 50 (see sleeve
or jacket 50, FIG. 5). However, sleeve 650 may also have an open
lower end 651 and may extend upward so as to substantially cover
second body portion 32 (compare FIG. 12A to FIG. 5) and engage
threads of a faucet. Thus, functionally, multiple channels 618
defined by ribs 616 may provide for sufficient contact of purged
water and sufficient drainage. The reason for maintaining close and
channeled contact is so that the heat transfer to the second
portion (to close valve), warming the second portion, will occur at
a quicker rate due to the contact with the warmer water).
The function of sleeve 650 is to provide structure for directing
water leaving the purge port when the valve opens (for example,
when the temperature drops to freezing), so that water leaving the
purge port is directed on the outside surface of the first body
portion (this will help close the valve, as when the valve opens,
ambient temperature is colder than the temperature of the water
flowing through the purge valve). However, the space between the
outer surface of the first body portion 30 and the inner surface
602 that is adjacent the first body portion cannot be too small or
water left over from the last freezing cycle could freeze and thus
block the flow of water from a subsequent cycle. If gap "G" is too
wide (or channel 618) is too deep, then water cannot be held close
enough to the surface of first body portion 30 to be effective for
heat transfer. The valve is typically oriented vertically or tilted
somewhat to the horizontal, or there could be debris at open bottom
end 606 that may clog the gap and act as a dam. Again, gap "G"
being too small or open end 606 being partially or wholly blocked
may create a place for water to accumulate and freeze before purged
water from a subsequent freeze is expelled from purge port 37.
Turning now to FIGS. 12A, 12B, 12C and 12D, it is seen that sleeve
650 may have an inner surface 602 and an outer surface 604. There
may be an upper open end 652 adjacent a threaded section 608, which
threaded section 608 may be configured to threadably receive the
threaded male outlet of an external or outside faucet--typically
designed to receive the female end of a garden hose (see FIG. 12D).
Sleeve 650 is seen to have a ribbed section 610 comprising multiple
ribs 616, which form, therebetween, multiple channels 618. Between
threaded section 608 and rib section 610 may be a shoulder 614 for
receiving a flat, elastomeric washer ("square O-ring") 611 (or
other fluid seal). Shoulder 612 is designed and configured to
snugly receive lip 41 at upper end of valve body 11 as seen in FIG.
12C. Sleeve upper section lies adjacent second body portion 2 and
upstream of channels 618.
Dor, diameter at O-ring, that is shoulder 614 is greater than Dl
diameter lip at shoulder 612, which is just large enough to snugly
receive lip 41. Diameter of upper body is larger than diameter from
rib to rib Drr. In FIG. 12C, "top" shows that the rib section 610
may go up at least to the bottom of the purge port 37, thus
allowing for satisfactory fluid flow between the purge port and the
channels. That is, purge port 37 may open to the channels. Gap G
(as seen in FIG. 12C) is the radial distance between the outer
surface of the lower body and the deepest point of the channel. In
some embodiments, gap "G" may be in the range of about 1.0 mm to
2.5 (more preferred about 0.50 mm-4.00 mm). Channel cross-section
area where it opens at the removed end may be in the range of about
0.25 mm.sup.2 to 20.00 mm.sup.2 (more preferred about 1.50
mm.sup.2-12.00 mm.sup.2). The number of channels may be 2 to 20. In
some embodiments, the innermost surface of the ribs is designed to
fit snugly against the outer surface of first body portion 30
against the outer surface of first body portion 30. Open bottom end
606 may be angled to help water drainage and help prevent
blockage.
Although the invention has been described with reference to
specific embodiments, this description is not meant to be construed
in a limiting sense. On the contrary, various modifications of the
disclosed embodiments will become apparent to those skilled in the
art upon reference to the description of the invention. The number
or order of O-rings or washers may be varied as necessary or
combined with the integrated seal for specific requirements. It is
therefore contemplated that the appended claims will cover such
modifications, alternatives, and equivalents that fall within the
true spirit and scope of the invention.
* * * * *